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Biomedical subjects

K Yasui

Publications and source records attributed to K Yasui.

At least 343 records · Page 19Linked to original sources
PubMed1982

Plasma pancreatic glucagon in pancreatic and primary diabetes, and liver cirrhosis: application of a correction to the radioimmunoassay for pancreatic glucagon.

Evidence is present that plasma contains non-specific factors which interfere with the 30K glucagon assays. A correction can be made for these interference factors because the factors can be quantitated following absorption of glucagon with charcoal-dextran. Using a correction factor the range of fasting plasma immunoreactive glucagon (IRG) in 12 totally pancreatectomized patients was below detectable limit. Fasting levels of IRG were determined on the plasma from 25 liver cirrhotics complicated by abnormal GTT, 13 pancreatic diabetics with chronic calcified pancreatitis (CCP), 25 adult-onset primary diabetics and 25 healthy subjects. When all samples were measured using no correction factor, the mean levels of IRG were 358 +/- 24 (mean +/- SE), 170 +/- 26, 178 +/- 16 and 178 +/- 7 pg/ml, respectively. Using a correction factor the mean level of IRG were 177 +/- 26, 16 +/- 4, 39 +/- 9 and 20 +/- 4 pg/ml, respectively. The mean values of the interference factor were not significantly different among all five groups. During an arginine infusion the interference factor remained unchanged despite an increase in IRG. It is available but not always necessary to apply a correction factor for 30K glucagon radioimmunoassay.

Aged↗
PubMed1982

Biological activities of the structural proteins of Japanese encephalitis virus.

Structural proteins V1, V2 and V3 of Japanese encephalitis virus (JEV) were isolated and purified by means of polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) and extracted from the sliced gel. The purified and renatured V3 envelope protein was found to bind to receptors for JEV on red blood cells. V3 also bound to haemagglutination inhibition (HI) antibodies from anti-JEV sera. In addition, V3 protein induced neutralizing antibodies against JEV when injected into mice. These facts strongly suggest that V3 protein carries the antigenic epitope(s) that elicit neutralizing antibodies and react with HI antibodies. We conclude the V3 plays an important role in virus infection. V2 protein did not exhibit these biological activities, but antibody against V1 protein, not contaminated with V3 protein, showed slight virus neutralizing activity. Possible implications of these results are discussed.

Animals↗
PubMed1982

Differences in biological activity of the V3 envelope protein of two Japanese encephalitis virus strains.

Two stains Nakayama-NIH and JaGAr-01 of Japanese encephalitis virus (JEV) distinctly differ in their virulence. Amino acid analysis of the V3 viral protein revealed different serine and tyrosine contents in JaGAr-01 V3 as compared to Nakayama -NIH V3. SDS-PAGE purified renatured JaGAr- and Nakayama-V3 proteins could absorb cross-reactive neutralizing antibodies present in anti-nakayama and anti-JaGAr hyperimmune sera. They also absorbed strain specific antibodies of anti-JaGAr and anti-Nakayama sera, respectively. These observations clearly suggest that both JEV strain specific and cross reactive antigenic determinants are present on V3 protein molecules. Antibody against purified Nakayama V3 protein neutralized Nakayama-NIH virus, but had little neutralizing activity against JaGAr-01 virus. The phenomenon is less pronounced when antibodies against Nakayama-NIH virions are used rather than those against purified homologous V3. This suggests that the antigenicity of the purified V3 protein differs from that of the intact virus envelope.

Amino Acids↗
PubMed1982

[Right and left ventricular systolic time intervals in patients with atrial septal defect measured by the ultrasonic Doppler method].

Noninvasive measurement of right and left ventricular systolic time intervals (STIs) was made utilizing ultrasonic Doppler method in 35 patients with secundum atrial septal defect (ASD) to evaluate their hemodynamic states. Using the Doppler signals relating to the opening and closure of the pulmonary and aortic valves, both right and left ventricular preejection periods (RPEP, LPEP) and ejection times (RVET, LVET) were measured. The same studies were carried out in 50 control healthy subjects. In patients of ASD without pulmonary hypertension (mean pulmonary arterial pressure less than 20 mmHg), RPEP did not differ significantly from that of healthy subjects, while RVET was significantly prolonged reflecting right ventricular volume overloading. In patients with pulmonary hypertension (mean pulmonary arterial pressure greater than or equal to 20 mmHg), RPEP was prolonged and RPEP/RVET was significantly higher than those in healthy subjects. These two parameters were correlated well with pulmonary arterial pressure. In both groups LVET was shorter and LPEP/LVET was larger than those of normal, suggesting low output state of the left ventricle. In 5 surgical cases, LVET was prolonged and LPEP/LVET decreased after operation, while the right ventricular STIs did not change significantly. With the pulmonary to systemic flow ratio (Qp/Qs), only RVET/LVET was correlated significantly, but with poor correlation coefficient (r = 0.47, p less than 0.01). These data may suggest that noninvasive measurement of combined right and left ventricular STIs is useful to assess the hemodynamic states of ASD, especially for evaluation of associated pulmonary hypertension.

Adolescent↗
PubMed1982

[Visualization of intramyocardial blood flow distribution with contrast echomyocardiography].

To assess intramyocardial blood flow distribution by the contrast echocardiographic technique, we studied the effect of intracoronary injections of contrast agents on the echo intensity of the myocardium. As fundamental experiments, we made injections of ICG, urografin, artificial blood (FC-43) and microsphere into the coronary artery in open chest dogs and observed the changes in echo density of the myocardium. Bolus injection of 10 ml ICG into the coronary artery produced little change in the myocardial echo intensity, but bolus injection of 10 ml urografin, FC-43 and microsphere into the left circumflex coronary artery (LCX) and left anterior descending coronary artery (LAD) immediately increased the echo intensity of the left ventricular posterior wall (LVPW) and interventricular septum (IVS), respectively. Enhanced echo areas correlated well with the regions perfused by LCX and LAD, respectively. Clinically, we recorded two-dimensional echocardiograms during coronary arteriography (CAG) in 10 patients. In six of the 10 patients, the echo intensity of IVS increased during left CAG and in four of eight patients the echo intensity of LVPW increased during right CAG. Contrast echomyocardiography, contrast enhanced echocardiography of the myocardium, proved a useful technique for the evaluation of intramyocardial blood flow.

Animals↗
PubMed1981

Progressive multifocal leukoencephalopathy. Neuropathology and virus isolation.

Mechanism of demyelination in progressive multifocal leukoencephalopathy (PML) was elucidated by demonstrating ultrastructurally the relationship between the affected glial cells and myelin sheaths. The myelinating cells in the central nervous system, namely oligodendroglias, were specifically attacked by PML-virus with eventual primary destruction of myelin sheaths. An attempt to isolate PML-virus from the autopsy material was made. The presence of virus particles in the extracts from the brain, reactions of virions with antibodies and evidence of virus proliferation in the primary human fetal glial cell culture were shown by various techniques including negative staining, immunofluorescence, immunoelectron microscopy, and electron micrography. The isolated virus was antigenically identical with JC type of papovaviruses.

Brain↗
PubMed1980

Structure and stability of complexes between poly-5-bromouridylic acid and 2,9-dimethyladenine or 2-methyladenosine.

The complexes formed between poly-5-bromouridylic acid (poly(BU)) and 2,9-dimethyladenine (m2m9A) or 2-methyladenosine (m2Ado) were investigated. The stoichiometry of the m2m9A-poly(BU) complex was found to be 1:1 as determined by equilibrium dialysis measurements. The CD spectra of the complexes showed the formation of helically ordered structure. This is also confirmed by the sharp melting profiles. A comparison of the CD spectra with that of poly(m2A) . poly(BU) complex revealed a close relationship of the helical structures for these three types of complexes. It was observed that the m2m9A was able to form a thermally more stable complex with the poly(BU) than the m2Ado did.

Adenine↗
PubMed1979

Benign duodenocolic fistula due to duodenal diverticulum: report of two cases.

Two cases of benign duodenocolic fistula resulting from duodenal diverticula are presented. In both cases, the diverticula were located on the outer border of the second portion of the duodenum. The upper gastrointestinal study is the easiest and most useful examination for diagnosis. Hypotonic duodenography and the barium enema complement the upper series and serve to differentiate benign from malignant fistulas.

Aged↗
PubMed1978

A criss-cross heart with concordant atrioventriculo-arterial connections. Report of a case.

A distinctive angiographic appearance is described in a case of "criss-cross" heart with concordant atrioventriculo-arterial connections. The atrial situs was normal, and the morphological right ventricle was superior to the left ventricle, and the ventricular septum was horizontal in position. Both ventricleswere connected by a small ventricular septal defect. The aorta was situated anteriorly and to the right of the pulmonary artery. Although the cardiac segment was the apparent [S,L,D] type, the heart had conconrdant atrioventriculo-arterial connections. The ventricular rotation of the solitus heart about the longitudinal and the anteroposterior axis affected the atrioventricular flows, the plane of the ventricular septum, the inflow and outflow tracts of the ventricles, the interrelationship of the great arteries, and the course of the left coronary artery. Using the recent definition of criss-cross heart, we classified the heart as solitus-concordant (l-rotated) -normal.

Arteries↗